Robert Griffin III is not only impressing on the field, he's also making an impression off it. The rookie quarterback's No. 10 jersey has sold more than any other player's in a single season since the NFL started keeping track six years ago, league spokeswoman Joanna Hunter told ESPN.com.

The metric is based on sales of jerseys on the Washington Redskins' official Internet store, NFLshop.com.

The NFL will not provide specific sales numbers but did say that Griffin moved into the top spot by overtaking Brett Favre, who previously held the record for most jerseys sold in a year twice -- with the New York Jets in 2008 and the Minnesota Vikings in 2009.